1. Field of the Invention
The present invention relates to a motor control device, and specifically relates to a motor control device that drives wheels of a vehicle, such as a battery-powered electric vehicle, a fuel cell-powered electric vehicle, or a hybrid vehicle which uses an engine in combination with electricity.
2. Description of Related Art
An electric vehicle may experience degradation in performance or malfunctions of a motor serving as a drive for a vehicle. This may significantly affect the travel performance or travel safety. In particular, for a drive device of a battery-powered electric vehicle, an IPM motor (Interior Permanent Magnet synchronous motor) that includes a neodymium magnet exhibiting a high efficiency performance is used in order to increase an endurance distance with a limited battery capacity. Further, to date, an in-wheel motor drive system has been proposed in which the temperature of a wheel bearing unit, a reducer unit and a motor unit may be measured and monitored for overload, to limit a drive current in/to the motor or a rotational frequency of the motor rotor according to the temperature measurements, for ensuring reliability (for example, Patent Document 1 listed below).
[Patent Document 1] JP Laid-open Patent Publication No. 2008-168790